There are already well known types of extinguishing chambers for the electric arc, characterized by the continuous presence, in the region where takes place the separation of the contacts belonging to the interrupting apparatus of which the same chamber is a part, of a constant magnetic field directed transversally to the plane along which the electric arc develops and generated by couples of permanent magnets located along the arc path with the purpose of causing its rapid elongation, together with its extinction at the first favorable passage through the natural zero value of the current flowing through it.
The object of the present invention is an improved extinguishing chamber of the type described above, suitable for operating immersed in an insulating electronegative gas, as sulphur hexafluoride or another similar gas.